How to Replace a Fuel Injector in a Nissan Maxima

The Nissan Maxima fuel injector uses pressure to mix fuel with air. This method rendered carburetors almost entirely obsolete during the late 1980s and allows the same hardware to be used with different fuels due to the fuel injector's programmable firmware. A fuel injector consists only of a nozzle and a valve; it still requires a pump to inject the fuel into the engine.
Difficulty: Moderately Challenging
Instructions
Things You'll Need
Fuel injector kit
Socket wrench set
Torque wrench
1

Select the new fuel pump for your Nissan Maxima. You will not only need to know the make and model, but also the engine size. Models made from 1981 to 1984 have a 2.4L or 2.8L diesel engine, and 1985 to 1999 models have a 3.0L engine in several different types and configurations. Models built from 2000 to 2003 have a 3.0L or 3.5L engine, and the Nissan Maxima has been equipped with a 3.5L engine since 2004.
2

Disconnect the negative cable from the battery with a socket wrench and relieve the fuel system pressure. Detach the vacuum hose and the intake manifold collector from the fuel pressure regulator.
3

Remove the fuel lines from the fuel rail with a socket wrench and unplug the fuel injector electrical connectors. Remove the fuel rail mounting bolts with a socket wrench and take out the fuel rail assembly from the intake manifold with the fuel injectors still attached.
4

Expand the retaining clips from the fuel injectors and push the injectors out of the fuel rail. Discard the old O-rings.
5

Lubricate the new O-rings with a thin coating of clean engine oil and install the new fuel injector by reversing the removal procedure.
6

Use a torque wrench to tighten the fuel rail mounting bolts in two stages. Torque the bolts to between 84 and 96 inch pounds first, and then torque them to between 16 and 19 foot pounds.